21442445 has 4 divisors (see below), whose sum is σ = 25730940. Its totient is φ = 17153952.

The previous prime is 21442439. The next prime is 21442451. The reversal of 21442445 is 54424412.

It is a semiprime because it is the product of two primes.

It is an interprime number because it is at equal distance from previous prime (21442439) and next prime (21442451).

It can be written as a sum of positive squares in 2 ways, for example, as 9066121 + 12376324 = 3011^2 + 3518^2 .

It is a cyclic number.

It is not a de Polignac number, because 21442445 - 2⁶ = 21442381 is a prime.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2144240 + ... + 2144249.

It is an arithmetic number, because the mean of its divisors is an integer number (6432735).

Almost surely, 2^21442445 is an apocalyptic number.

It is an amenable number.

21442445 is a deficient number, since it is larger than the sum of its proper divisors (4288495).

21442445 is an equidigital number, since it uses as much as digits as its factorization.

21442445 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4288494.

The product of its digits is 5120, while the sum is 26.

The square root of 21442445 is about 4630.5987733769. The cubic root of 21442445 is about 277.8165421753.

Adding to 21442445 its reverse (54424412), we get a palindrome (75866857).

The spelling of 21442445 in words is "twenty-one million, four hundred forty-two thousand, four hundred forty-five".